The RCBS 3 Way Cutter head is a must for case trimming. Performing three functions at once, the RCBS 3 Way Cutter trims the case to length, chamfers the inside of the case mouth, and deburrs the outside of the case mouth, meaning taht you only have to handle the case one time! The cutter head is responsible for trimming to length, the caliber specific pilots are responsible for chamfering, and fit into the cutter head like any other pilot. The deburring cutter is adjustable for every caliber with a convenient thumb screw, and set screw. Changing calibers requires only adjusting the deburring cutter, and replacing the caliber-specific chamfer pilot.